This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We propose to: 1. Continue to determine the kinetic profiles of B-CLL cells of untreated patients, from the bone marrow and the blood, to identify the proliferating cells in B-CLL and to correlate these data with specific features of B-CLL cells, clinical course, and the various available prognostic markers. In some instances, subjects previously analyzed for leukemic cell kinetics will be re-studied to determine if birth and death rates have changed. 2. Determine the kinetic profiles of normal blood B cell subsets from healthy aging subjects. The reason for this is to determine any environmental factors that are associated with aging, 50 years or older. 3. Compare the kinetic profiles of B-CLL cells with those of B cell clonal amplifications detectable in some normal aging individuals and unaffected family members who are genetically informative relatives of B-CLL patients. We are looking for genetically similar adults 18 years or older to determine factors that are associated with the development of CLL as well as environmental factors that are associated with aging. 4. Analyze the proliferating B-CLL cells, and the clonally expanded normal B cells from elderly individuals and unaffected family members who are genetically informative relatives of B-CLL patients, for the presence of cytogenetic abnormalities that differ from those of the resting B-CLL pool.